This invention relates to impact pulverizers and, more particularly, to an impact pulverizer having an impact rotor mounted for rotation within a reduction chamber for striking pieces of pulverizable material and propelling the same radially of the chamber so that they impinge on the interior surfaces thereof.
Impact pulverizers have been known heretofore for the reduction in size of rock, metal ore and like materials. Apparatus of this type are useful in that they combine the crushing or pulverizing and classification functions in a single unit. No grinding of the material occurs, the pulverizing or attrition being caused by the particles striking impact means disposed within the interior of the apparatus and also, by the particles striking each other.
A pulverizing mill of the above-mentioned type is disclosed in Francis Pat. No. 3,887,141. This patent discloses an impact-attrition mill utilizing rotors having axially parallel impact bars for flinging ore material against axially oriented angular members depending inwardly from the walls of a primary reduction chamber within which the impact rotor is non-concentrically mounted. Ore material fed to the rotor longitudinally fully across the same is shattered by impaction against the impact bars on the rotor. After primary reduction is obtained, a secondary reduction occurs when the particles are flung into contact with other breaker bars in an axially centrally positioned secondary reduction chamber. The Francis device, however, is relatively slow acting and requires a large amount of power.
Accordingly, it is the primary purpose of the present invention to provide an impact pulverizer of the type heretofore described which acts faster and requires less power than those heretofore known.
It is a further object of the present invention to provide such an apparatus that can be used as an impact mill for a wide variety of materials, including all types of rock, ore, glass, bark and wood waste.
It is a further object of the present invention to provide an improved method of comminuting pulverizable material, which method will be faster and more efficient than those heretofore known and will require less power.